The present invention relates to a cooking appliance of the type comprising two electric cooking plates or xe2x80x9chot platesxe2x80x9d disposed face to face and connected together via a hinge.
It is applicable particularly, but not exclusively, to cooking appliances of the waffle-iron or steak-grill type made up of two hot plates which are mounted to pivot relative to each other, and between which the food to be cooked is placed.
Currently, appliances of that type require manual action to move the plates apart in order to place food between them or remove food from between them, or in order to inspect the progress of the cooking. That solution is impractical for various reasons. The manual handling necessary to open and close the appliance is inconvenient. Risks of suffering burns ensue. Cooking time is left to the appreciation of the user. There is therefore no repeatability in the cooking quality obtained.
In addition, in most currently available appliances, the cooking temperature is regulated by an electromechanical thermostat (which can be fixed or adjustable) which offers accuracy to within no better than 50xc2x0 C. for the hot plate temperature, which does not make it possible to obtain uniform cooking results.
Patent Document GB 621 155 discloses an electrical cooking appliance having a lid, a thermostat making it possible to adjust the temperature, and a clockwork mechanism which makes it possible to define a cooking time, and which causes the lid to open and stops the heating when the cooking time has elapsed.
Patent Document U.S. Pat. No. 2,936,697 describes another electrical cooking appliance closed by a lid, the lid in that appliance being opened automatically and heating being stopped automatically at the end of the cooking cycle, those operations being triggered by expansion of a bimetallic strip subjected to the cooking temperature.
Such appliances use opening mechanisms that are complex and therefore costly, and cooking temperature regulation means that suffer from the above-mentioned drawbacks.
An object of the present invention is to eliminate those drawbacks. To this end, the present invention provides a cooking appliance of the type comprising:
a housing made up of a bottom shell and of a top shell fixed together via a hinge, and held spaced apart by first resilient return means;
at least one hot plate disposed inside the housing;
locking means for holding the housing closed against the drive from the return means;
setting means for setting cooking parameters; and
control means for controlling the locking means so as to put them into the unlocked position as a function of the cooking parameters, thereby causing the housing to open under drive from the return means.
In the invention, said cooking appliance is characterized in that the locking means comprise:
a locking piece associated with one of the shells so as to be movable between an unlocked position and a locked position in which it co-operates with a locking finger secured to or integral with the other shell to hold the housing in the closed position;
second resilient return means for returning the locking piece into the unlocked position; and
an electromagnet controlled by the control means so as to hold the locking piece in the locked position.
By using a single moving locking piece and an electromagnet, the invention thus enables such cooking appliances to be made much more simply, without requiring heavy and voluminous control means.
The appliance may have two hot plates which are mounted in respective ones of the two shells of the housing, and between which the food to be cooked is disposed.
Advantageously, the appliance of the invention further comprises a processor connected to the setting means for setting the cooking parameters, and designed to control the electromagnet as a function of the cooking parameters.
In a feature of the invention, the appliance is provided with an electrical contact actuated by the housing opening, and connected to the processor to enable it to detect the position of the housing, i.e. whether it is open or closed.
In another feature of the invention, the hot plates are coupled to electrical heater elements, the appliance further being provided with a relay controlled by the processor to control delivery of electrical power to the elements.
In yet another feature of the invention, the hot plates are associated with a temperature sensor connected to the processor which is provided with means for controlling delivery of power to the electrical heater elements of the hot plates so as to maintain them at a setpoint temperature, the setting means being designed to define a setpoint temperature for the cooking cycle.